Compact sensors have many uses, such as door, state, temperature, and/or acceleration sensors that might be inexpensively deployed, perhaps in a communications network. Typically, some sensors require some processing, communications capability and a power source to be nearby the sensor. In some applications, that power source is a battery and the sensor usage and lifetime are such that available battery power can be exhausted and need battery replacement. In some aspects, traditional sensors may provide certain methods of warning a user of a low-battery state of the device, such as chirping sounds from a smoke detector.
The minimum duration of such a chirping period may be dictated by regulations, laws, other rules, or consumer expectations. In order to allow for different battery chemistry, smoke detectors may be configured to chirp for significantly longer than this minimum duration when using most batteries. This may be inefficient and result in batteries being changed earlier than is necessary.
It would be useful to modify the timing of the warning to account for other factors, so that the warning can be triggered later than it would otherwise and/or earlier than it would otherwise.